207 research outputs found
Interest Rate Smoothing and Macroeconomic Instability under Post-Capital Account Liberalization Turkey
Cataloged from PDF version of article.This paper considers the interest rate policy of the Central Bank of the Republic of Turkey (CBRT) in the post-financial liberalization and deregulation era. We find that (1) the Bank's interest rate smoothing tendency is the main determinant of its monetary policy in this period, (2) the CBRT does not seem to be responsive to the developments in real economy (output), and (3) although inflation targeting central banks are not supposed to pay attention to exchange rates, the CBRT appears to be slightly responsive to changes in real exchange rate. In answer to the question of whether there is a deeper underlying Structural constraint binding the CBRT's "independence," it seems clear that the global financial system is restricting the ability of the central banks to pursue "independent" policy objectives
Analysis of Security Overhead in Broadcast V2V Communications
This paper concerns security issues for broadcast vehicle to vehicle (V2V) messages carrying vehicle status information ((location, heading, speed, etc.). These are often consumed by safety-related applications that e.g. augment situational awareness, issue alerts, recommend courses of action, and even trigger autonomous action. Consequently, the messages need to be both trustworthy and timely. We explore the impact of authenticity and integrity protection mechanisms on message latency using a model based on queuing theory. In conditions of high traffic density such as found in busy city centres, even the latency requirement of 100ms for first generation V2V applications was found to be challenging. Our main objective was to compare the performance overhead of the standard, PKC-based, message authenticity and integrity protection mechanism with that of an alternative scheme, TESLA, which uses symmetric-key cryptography combine with hash chains. This type of scheme has been dismissed in the past due to sup-posed high latency, but we found that in high traffic density conditions it outperformed the PKC-based scheme. without invoking congestion management measures. Perhaps the most significant observation from a security perspective is that denial of service attacks appear very easy to carry out and hard to defend against. This merits attention from the research and practitioner communities and is a topic we intend to address in the future
Structural Assessment of the 13th Century Great Mosque and Hospital of Divrigi: A World Heritage Listed Structure
The Great Mosque and Hospital of Divrigi is located in the central eastern part of Turkey, in Divrigi, Sivas. The historical facility consists of a monumental mosque and a two-story hospital, which are adjacent to each other. The structure dates back to 13th century Mengujekids period and has been listed by the UNESCO as a World Heritage since 1985. Great Mosque and Hospital of Divrigi is particularly notable for its monumental stone portals that are decorated with three-dimensional ornaments carved from stone. The structural system of the monument consists of multi-leaf stone masonry walls and stone piers that support the roof structure which consists of stone and brick arches and vaults. The structure is located about 90 km away from the North Anatolian Fault Line, that has been causing several destructive earthquakes. Consequently, the structure is prone to destructive seismic activities. In this study, after a brief introduction on the structural system and current condition of the structure, the structural performance of the Great Mosque and Hospital of Divrigi is investigated through site observations and structural analyses. For this purpose, linear and nonlinear 3D finite element models of the structure are developed and the structure is examined under the effects of vertical loads and seismic actions. In the light of the analyses results, recommendations for potential interventions are outlined for further preservation of the structure
A novel investigation method for axonal damage in neuromyelitis optica spectrum disorder: In vivo corneal confocal microscopy
BACKGROUND: Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory autoimmune disorder that damages optic nerves, brainstem, and spinal cord. In vivo corneal confocal microscopy (IVCM) is a noninvasive technique that provides corneal images with dendritic cells (DCs) and corneal subbasal nerve plexus (SBP), which arises from the trigeminal nerve. OBJECTIVE: We investigated corneal SBP changes in NMOSD and proposed IVCM as a potential new disease severity biomarker for NMOSD. METHODS: Seventeen age-sex matched NMOSD patients and 19 healthy participants underwent complete neurologic and ophthalmologic examinations. The duration of disease, first symptom, presence of optic neuritis attack, antibody status, Expanded Disability Status Scale(EDSS) score and disease severity score(DSS) were recorded. Retinal nerve fibre layer (RNFL) thickness was measured with optical coherence tomography, and corneal SBP images were taken with IVCM. RESULTS: NMOSD patients had significantly reduced corneal nerve fibre lenght-density and corneal nerve branch lenght-density compared with controls, while DC density was increased. NMOSD patients also showed significantly reduced RNFL thickness compared with controls. EDSS,DSS levels were inversely correlated with IVCM parameters. CONCLUSION: We observed significant corneal nerve fibre loss in NMOSD patients in relation to disease severity. IVCM can be a candidate noninvasive imaging method for axonal damage assessment in NMOSD that warrants further investigation
Effect of curing time on selected properties of soil stabilized with fly ash, marble dust and waste sand for road sub-base materials
The properties of sub-base filling materials in highway construction are essential, as they can determine the performance of the road in service. Normally, the existing materials are removed and replaced with new materials that have adequate load-bearing capacity. Rising environmental concern and new environmental legislations have made construction professionals consider other methods. These methods include stabilizing the existing materials with other additives to improve their performance. Additives can be waste materials generated by different industries. In this work, the existing excavated soil is stabilized with waste materials. The wastes consisted of fly ash, marble dust and waste sand. The percentage addition of waste materials was 5%, 10%, 15% and 20% (by mass) of the existing soil. The soil/waste specimens were cured for 1, 7, 28, 56, 90 and 112 days before testing. Testing included the dry unit weight and unconfined compressive strength ( qu) as well as X-ray diffraction analysis and scanning electron microscopy observation. Also, the California Bearing Ratio values were obtained and are reported in this investigation. The results showed that the qu values increased with the increase in waste materials content. Also, there is tendency for the dry unit weight to increase with the increase in waste materials
Detecting imipenem resistance in Acinetobacter baumannii by automated systems (BD Phoenix, Microscan WalkAway, Vitek 2); high error rates with Microscan WalkAway
<p>Abstract</p> <p>Background</p> <p>Increasing reports of carbapenem resistant <it>Acinetobacter baumannii </it>infections are of serious concern. Reliable susceptibility testing results remains a critical issue for the clinical outcome. Automated systems are increasingly used for species identification and susceptibility testing. This study was organized to evaluate the accuracies of three widely used automated susceptibility testing methods for testing the imipenem susceptibilities of <it>A. baumannii </it>isolates, by comparing to the validated test methods.</p> <p>Methods</p> <p>Selected 112 clinical isolates of <it>A. baumanii </it>collected between January 2003 and May 2006 were tested to confirm imipenem susceptibility results. Strains were tested against imipenem by the reference broth microdilution (BMD), disk diffusion (DD), Etest, BD Phoenix, MicroScan WalkAway and Vitek 2 automated systems. Data were analysed by comparing the results from each test method to those produced by the reference BMD test.</p> <p>Results</p> <p>MicroScan performed true identification of all <it>A. baumannii </it>strains while Vitek 2 unidentified one strain, Phoenix unidentified two strains and misidentified two strains. Eighty seven of the strains (78%) were resistant to imipenem by BMD. Etest, Vitek 2 and BD Phoenix produced acceptable error rates when tested against imipenem. Etest showed the best performance with only two minor errors (1.8%). Vitek 2 produced eight minor errors(7.2%). BD Phoenix produced three major errors (2.8%). DD produced two very major errors (1.8%) (slightly higher (0.3%) than the acceptable limit) and three major errors (2.7%). MicroScan showed the worst performance in susceptibility testing with unacceptable error rates; 28 very major (25%) and 50 minor errors (44.6%).</p> <p>Conclusion</p> <p>Reporting errors for <it>A. baumannii </it>against imipenem do exist in susceptibility testing systems. We suggest clinical laboratories using MicroScan system for routine use should consider using a second, independent antimicrobial susceptibility testing method to validate imipenem susceptibility. Etest, whereever available, may be used as an easy method to confirm imipenem susceptibility.</p
The global impact of the COVID-19 pandemic on the management and course of chronic urticaria
Introduction: The COVID-19 pandemic dramatically disrupts health care around the globe. The impact of the pandemic on chronic urticaria (CU) and its management are largely unknown. Aim: To understand how CU patients are affected by the COVID-19 pandemic; how specialists alter CU patient management; and the course of CU in patients with COVID-19. Materials and Methods: Our cross-sectional, international, questionnaire-based, multicenter UCARE COVID-CU study assessed the impact of the pandemic on patient consultations, remote treatment, changes in medications, and clinical consequences. Results: The COVID-19 pandemic severely impairs CU patient care, with less than 50% of the weekly numbers of patients treated as compared to before the pandemic. Reduced patient referrals and clinic hours were the major reasons. Almost half of responding UCARE physicians were involved in COVID-19 patient care, which negatively impacted on the care of urticaria patients. The rate of face-to-face consultations decreased by 62%, from 90% to less than half, whereas the rate of remote consultations increased by more than 600%, from one in 10 to more than two thirds. Cyclosporine and systemic corticosteroids, but not antihistamines or omalizumab, are used less during the pandemic. CU does not affect the course of COVID-19, but COVID-19 results in CU exacerbation in one of three patients, with higher rates in patients with severe COVID-19. Conclusions: The COVID-19 pandemic brings major changes and challenges for CU patients and their physicians. The long-term consequences of these changes, especially the increased use of remote consultations, require careful evaluation
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